## Send a message

`POST /v1/chats/:dialogId/messages`

Sends a text message to the given dialog. The text supports BB codes for formatting; you can attach a keyboard and attachments to the message.

## Parameters

| Parameter | Type | Req. | Description |
|----------|-----|:-----:|---------|
| `dialogId` (path) | string | yes | Dialog identifier. Numeric user ID for personal messages, list — [`GET /v1/users`](/docs/entities/users). `chatXXX` for group chats. Accepts the value `me` — see below |

**The `me` alias.** Instead of a numeric user ID you can pass the string `me`: the dialog opens with the current key owner. Learn more in [Chats and messages](/docs/chats).

## Request body fields

| Field | Type | Req. | Description |
|------|-----|:-----:|---------|
| `message` | string | yes | Message text (up to 20,000 characters). Supports BB codes |
| `attach` | array | no | Attachments: cards, tables, images, files, dividers |
| `keyboard` | array | no | Interactive buttons under the message |
| `menu` | array | no | Message context menu items |
| `replyId` | number | no | ID of the quoted message |
| `system` | boolean | no | When `true` — system style (no avatar, `authorId = 0`) |
| `urlPreview` | boolean | no | When `false`, disables link preview in the text |

## Message layout

- [Text formatting](/docs/chats/messages/formatting) — BB codes: bold, italic, links, color
- [Keyboard](/docs/chats/messages/keyboard) — interactive buttons under the message
- [Attachments](/docs/chats/messages/attach) — cards, tables, images, files

## Examples

In the examples, `dialogId` is `42` — the recipient's numeric user ID.

### curl — personal key

```bash
curl -X POST https://vibecode.bitrix24.com/v1/chats/42/messages \
  -H "X-Api-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "message": "Invoice issued. Please await confirmation."
  }'
```

### curl — OAuth application

```bash
curl -X POST https://vibecode.bitrix24.com/v1/chats/42/messages \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "message": "Invoice issued. Please await confirmation."
  }'
```

### JavaScript — personal key

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/42/messages', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    message: 'Invoice issued. Please await confirmation.',
  }),
})

const { success, data } = await res.json()
console.log('Message ID:', data)
```

### JavaScript — OAuth application

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/42/messages', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_APP_KEY',
    'Authorization': 'Bearer USER_SESSION_TOKEN',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    message: 'Invoice issued. Please await confirmation.',
  }),
})

const { success, data } = await res.json()
console.log('Message ID:', data)
```

## Response fields

| Field | Type | Description |
|------|-----|---------|
| `success` | boolean | Always `true` on success |
| `data` | number | ID of the created message |

## Response example

```json
{
  "success": true,
  "data": 36889
}
```

## Error response example

422 — Bitrix24 returned an error (dialog not found or unavailable):

```json
{
  "success": false,
  "error": {
    "code": "BITRIX_ERROR",
    "message": "Dialog not found"
  }
}
```

## Errors

| HTTP | Code | Description |
|------|-----|---------|
| 400 | `MESSAGE_REQUIRED` | The `message` field is empty and there is no `attach` block. A common cause is text passed under an unknown field name, for example `text`. `message` lists the unrecognized fields |
| 422 | `BITRIX_ERROR` | Bitrix24 returned an error — dialog not found or unavailable (details in `message`) |
| 502 | `ME_ALIAS_RESOLUTION_FAILED` | `dialogId=me` — failed to resolve the current user's ID |
| 403 | `SCOPE_DENIED` | The key does not have the `im` scope |
| 401 | `TOKEN_MISSING` | The key has no configured tokens |

Full list of common API errors — [Errors](/docs/errors).

## Known specifics

**System messages.** When `system: true`, the message is shown without the sender's avatar and the `authorId` field equals `0`. Such a message cannot be edited or deleted via the API.

**Long text truncation.** Text longer than 20,000 characters is truncated to 20,000, with ` (...)` appended at the end.

## See also

- [Messages](/docs/chats/messages)
- [Edit a message](/docs/chats/messages/update)
- [Delete a message](/docs/chats/messages/delete)